Adjustable combustion chamber control



. June 30, 1931. F. A. TALBOT ADJUSTABLE COMBUSTION CHAMBER CONTROL Original Filed May 11, 1927 m4 lllllllil 3.

i Patented June 30, 1931.

UNITED STATES PATENT OFFICE FRANK A. TALBOT, OF GBEENVILLE, SOUTH CAROLINA, ASSIGNOR 0F FORTY-FOUB ONE-HUNDREIYI'HS '10 HENRY H. HARRIS, 0F GREENVILLE, SOUTH CAROLINA, AND

ELEVEN ONE-HUNDB-ED'IHS '10' GRAHAME H. POWELL, OF

OF OOLUMBIA WASHINGTON, DISTRICT ADJUSTABLE COMBUSTION CHAMBER-CONTROL Application filed May -11, 1927, Serial No.,,190,558. Renewed October 17, 1930.

The essence of the present invention lies in the provision of means to control an adjustable combustion chamber in an internal combustion engine, not only in dependence'upon the throttle position, but also in dependence upon the engine load. The principal objects of the invention are to secure uniform operatingefliciency of the engine and economy. of fuel consumption, and it is particularly applicable to the engines of automotive vehicles.

Assuming that a motor is designed to operate on a certain compression pressure under full load at open throttle, it is obvious that as the throttle is moved to closed position, the combustion space remaining the same, the compression pressure lowers so that full efiiciency is not obtainedfrom gases not compressed to a sufficiently high pressure. lhis is due to the fact that when the throttle is closed, there is great resistance to the inflow of the combustion gases, and hence, only a small amount of gas is admitted. This small amount is not sufficient'to fill the cylinder, and the result is a very low compression pressure.

ablevacuum in the intake manifold, I base Thus the quantity of combustion gases varies to a considerable extent between open and closed throttle. As the throttle approaches closed position, gases drawn into the combustion chamber becomes more and more rarified, and when the size of the combustion chambers remains constant, the gases are accordingly less and less compressed.

, Thus, the degree of compression at the momy remedial structure upon this factor itself.

An'embodiment of my invention is illus trated on the accompanying sheet of draw ing, of which the single figure represents a cross-section through a cylinder of an internal combustion engine provided with my improved control device.

Referring to the-drawing, 1 indicates an as to ful internal combustion engine cylinder, the ordinary cylinder head being removed and replaced by a member 2 provided with a cylindrical aperture 3 co-axial with the cylinder 1. For the rest, member 2 is of the same gen eral desifgl'n as the ordinary cylinder head so latter. A solid, slidable piston 4 is disposed 11 all the collateral functions of the I in opening 3, and is provided with usual packing means such as piston rings 5. The

function of piston 4 is that of cylinder head, and it will be hereinafter referred to as such. Posts 6 and 7 are rigidly secured in head 4, diametrically spaced and extending 'up- 'wardly parallel to the cylinder axis. A yoke 8 connects these posts at their tops and is held in position by means of nuts threaded to the ends of the posts.

Ashaft 9 is journalled in suitable bearing blocks 10 and 11 so as to extend above the head 4 within theframe outlined by it, the

posts, and the yoke. An eccentric 12 is rigidly secured to. shaft 9and has bearing both on the under surface of yoke 8 and on the top surface of head 4. An arm 13 is likewise rigidly secured to shaft 9 and extends to some extent past the cylinder 1.

Beneath the free end of arm 13 is rigidly secured a cylinder 14 with its axis parallel to that of cylinder 1. A piston 15 is arranged for axial movement within cylinder 14, and is connected with the free, end of arm 13 by a connecting rod 16, the latter being pivoted to both of the elements. Tubing 17 is arranged to extend between an aperture in thebottom of cylinder 14 and a tap in the intake manifold 18 between throttle valve, 19 and the combustion chamber, and means such as spring 20 are arranged to hold arm 13 in v the dotted line position when the engine is inoperative.

Upon starting the engine at low throttle, the comparatively high state ofvacuum existing in the intake manifold will immediatel v pull piston 15 down into the positionillustrated against the action of spring 20.

As the throttle is opened and the vacuum decreases, spring 20 will progressively lift piston 15 and therewith arm 13. The'eccentric 12, of course, follows all movements of am 15. Thus, with high vacuum existing in the manifold, piston head 4 will be in its lowermost position, as indicated, and will be pro gressively lifted in direct dependence upon the fall of vacuum as the throttle is opened.

In the above description, a constant load has been assumed. Suppose the load to increase, however, at any throttle position, the vacuum in the manifold will be accordingly decreased in dependence upon the slower motor speed. This being the case, piston 15 will move up imparting the same movement to piston 4. Under these circumstances, a larger charge will be admitted into the combustion space and increased power will result.

The mechanical advantage of the transmission means between piston 15 and piston 4 is so designed that explosion impulses on piston 4 will have no appreciable vibratory effect on piston 15. Auxiliary damping devices may, of course, be provided but piston 15 is itself in efi'ect a dash-pot.

When arm 13 is in its dotted line position with the engine operating there is a relatively small degree of vacuum in chamber 14, the vacuum increasing as the throttle is closed. It will be noted, however, that when arm 13 is in its uppermost position, eccentric 12 is in its position of maximum mechanical advantage relative to the cylinder head, this advantage decreasing as the arm moves downwardly. This variable leverage effect is of great importance in securing a substantial equilibrium between the force of the motor explosions and the suction force acting in opposite directions on piston 15. By properly designing the transmitting connections between piston 15 and head 4, the oppositely acting force may be substantially balanced at all engine loads and speeds. Under these conditions spring 20 may be entirely dispensed .with since upon an opening movement of throttle 19 the cylinder explosions will overbalance the vacuum acting oniston 15 to move piston head 4 outwardly. n the other hand, when the throttle is moved in a closing direction the vacuum acting on piston 15 will momentarily overcome the force of the cylinder explosions acting on head 4 so that the latter will be moved inwardly. It is obvious that a spring 20 will be necessary only when intake suction continually overbalances mean explosion force, and that the two forces may be balanced for all ranges b portioning the illustrate means.

The above disclosure is, of course, merely intended to be illustrative of the general principles of my invention. I do not intend to properly protransmission restrict myself to any structure other than that determined in the following claims:

I claim:

1. In an internal combustion engine having a cylinder, a head for said cylinder movable axially relative thereto, a suction intake conduit in connection with said cylinder, and a valve in said conduit, the combination of an expansible chamber device in communication with said conduit intermediate said valve and cylinder, means tending yieldably to hold the movable element of said device outwardly thereof, an eccentric for reciprocating said cylinder head, a lever in rigid connection with said eccentric, and connecting means between said lever and the movable element of said expansible chamber device, whereby movements of said element responsive to the variable state of vacuum in said conduit are transmitted to said cylinder head.

2. p In an internal combustion engine having an adjustable combustion chamber including and adjustable wall and a suction intake conduit, an element actuated in direct dependence upon the vacuum variations in the intake conduit, and a motion transmitting connection between said wall and element moved by the vacuum actuated elementto contract the combustion chamber without the assistance of any other force extrinsic to the engine, said connection having a variable mechanical advantage which is at its maximum at the initiation of the combustion chamber contraction.

3. In an internal combustion engine having a cylinder and a combustion chamber therein, a movable member bounding a ortion of said combustion chamber and adJustable conduit, and a motion transmitting connection between said device and said movable member whereby movements of said device in dependence upon vacuum increases in the conduit are positively imparted to the movable member to contract the combustion chamber without the assistance of any force extrinsic" to the engine.

4. In an internal combustion engine, a cylinder, a head for said cylinder axially movable relative thereto, a suction intake conduit, means actuated in direct dependence upon the vacuum variations in the intake conduit, andv a motion transmitting connection between said vacuum actuated means and saidcylinder head whereby movements of said vacuum actuated means in dependence upon vacuum increases in the conduit are positively imparted to the cylinder head to move the latter inwardly of the'cylinder without the assistance of any other force'extrinsic to the engine.

5'. In an internal combustion engine having a combustion chamber, a movable member bounding a portion of said combustion chamber and adjustable to contract or expand the latter, a suction intake conduit in connection with the combustion chamber, a device having a chamber in communication with said conduit whereby said device is contracted in dependence upon vacuum increases in the conduit, and a positive mechanip cal connection between said device and said movable member whereby contracting movements of said device are positively transmitted to said movable member to contract the combustion chamber without the assistance of any other force extrinsic to the engine,;said connection having a variable mechanical advantage which is at its maximum at the initiation of the combustion chamber contraction.

6. In an internal combustion engine having a cylinder and a combustion chamber therein, a movable member bounding a portion of said combustion chamber and adjustable to contract or expand the latter, 'a suction intake conduit in connection with said chamber, a device having a chamber in connection with said conduit whereby said device 'is contracted in dependence upon vacuum increases in the conduit, means acting to expand said device upon vacuum decreases in the conduit, and positive transmission means between said device and said movable member whereby movements of said device in either direction are communicated to said movable member.

7. In an internal combustion engine, a cylinder, a head for said cylinder axially movable relative thereto, a suction intake conduit in connection with the cylinder, a device having a chamber in connection with said conduit whereby said device is contracted in dependence upon vacuum increases in the conduit, means acting to expand said device upon vacuum decreases in the conduit, and positive transmission means between said device and said head whereby movements of said device in either direction are communicated to said head.

8. In an internal combustion engine having a cylinder and a combustion chamber therein, a movable member bounding a portion of said combustion chamber and adjustable to contractor expand the latter, a suction intake conduit in connection with said chamber, a device having a chamber in connection with said conduit whereby said device is contracted in dependence upon vacuum increases in the conduit, means acting to expand said device upon vacuum decreases in the conduit, and a positive mechanical connection between said device andsaid movable member whereby movements of said device in either direction are communicated to said movable member.

a. In an internal combustion engine having a cylinder and a combustion chamber therein, a movable member bounding a portion of said combustion chamber and adjustable to contract or expand the latter, a suction intake conduit in connection with said chamber, a device having a chamber in connection with said conduit whereby said device is contracted in dependence upon vacuum increases in the conduit, and a motion transmitting connection between said device and said movable memberv whereby movements of said device in dependence upon vacuumincreases in the conduit are positively imparted to the movable member to contract the combustion chamber" without the assist-' ance of any force extrinsic to the engine, said connection having a variable mechanical advantage which is at its maximum at the initiation ofthe combustion chamber contraction.

10. In an internal combustion engine, a cylinder, a head for said cylinder axially movable relative thereto, a suction intake conduit, means actuated in direct dependence upon the vacuum variations in the intake conduit, and a motion transmittingconnection between said vacuum actuated means and said cylinder head whereby movements of said vacuum actuated means in dependence upon vacuum increases in the conduit are positively imparted to the cylinderhead to move the latter inwardly of the cylinder without the assistance of any other force extrinsic to the engine, said connection having a variable mechanical advantage which is atits maxi-. mum at the initiation of the combustion chamber contraction.

In testimony whereof I have hereunto set FRANK A. TALBOT.

. my hand. 

